| Method of sealing a glass envelope -> Monitor Keywords |
|
|
  Method of sealing a glass envelopeUSPTO Application #: 20070188757Title: Method of sealing a glass envelope Abstract: A method of sealing a glass package comprising providing a first glass substrate, the first substrate having first and second alignment marks. A second glass substrate having third and fourth alignment marks is aligned to the first substrate by translating the first substrate relative to the second substrate, and aligning the second and fourth alignment marks by rotating the first substrate relative to the second substrate. (end of abstract) Agent: Corning Incorporated - Corning, NY, US Inventors: Jeffrey Michael Amsden, Puthiya Kottal Saquib Mohamed, Aiyu Zhang USPTO Applicaton #: 20070188757 - Class: 356401 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20070188757. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001]This application claims the benefit of priority under 35 U.S.C. .sctn.119(e) of U.S. Provisional Application Ser. No. 60/773399 filed on 14 Feb. 2006, the contents of which are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION [0002]1. Field of the Invention [0003]The present invention relates generally to sealing a glass envelope, and particularly to sealing glass substrates with a frit. [0004]2. Technical Background [0005]Organic light emitting diode displays offer an attractive alternative to LCD and plasma based display technologies. However, the organic light emitting elements of the display devices are susceptible to damage from exposure to moisture (humidity) and oxygen, and therefore must be hermetically sealed within an appropriate envelope to prevent exposure to such environmental hazards. The hermetic seal must be robust enough to protect the organic material over the lifetime of the device incorporating the display (e.g. television, cell phone, etc.). [0006]Glass envelopes are an ideal container in which to encase the OLED device. Such envelope may be sealed using an epoxy, or other adhesive material, but more recently, sealing via a glass frit disposed between the substrates comprising the display has proven to be a desirable alternative, owing at least in part to the hermetic nature of the glass seal formed by the frit. Nevertheless, as the applications for OLED displays increase in size, from camera and cell phone screens to larger devices, such as televisions, the size of the substrates used to manufacture such devices must also increase in size to provide the necessary economies of scale. That is, equipment manufacturers typically deposit a plurality of display devices between two substrate, seal the substrates, then separate (divide) the sealed substrates into a plurality of finished display devices. Hermetically sealing a plurality of OLED display devices between two substrates repeatedly, with a high degree of precision, has proven challenging. [0007]As described above, because the organic layers of the OLED display device are susceptible to damage from heat, the frit used to form the seal between the glass substrates cannot be heated in an oven, since the heat would be applied equally to the frit and to the organic materials. Sealing the frit by traversing the frit with a laser, thereby heating the frit and forming the hermetic seal is the desired approach. [0008]A current method of laser sealing alignment is to align the laser to each cell (each frit frame) manually prior to sealing, which is time consuming and has potential for human error. This manual process also relies on the edges of the substrates as markers for alignment. The lateral and rotational tolerance of the cells containing the OLED devices with respect to the substrate edges and fritted cover sheets is not repeatable enough for the glass edges to be used for alignment of large size substrates containing a multiplicity of OLED devices. As the size and/or number of cells per substrate increases, and hence the size of the sheets, the need to align the entire substrate to the fritted cover sheet becomes critical for efficiency, precision and yield. The alignment of the OLED devices to the frit forming each cell is critical to ensure the hermeticity of the seal [0009]In some processes magnets have been used as a method to apply a force between the OLED-containing substrate and the fritted cover sheet during laser sealing. However, magnets are not practical for large substrate sizes. In addition, magnets have been identified as an enhancer of Newton's Rings within sealed substrates due to their non-uniform force on the substrates. A process and equipment that applies a uniform repeatable force over the entire substrate, and which is capable of repeatable, precise alignment of the substrate components is therefore desirable. SUMMARY OF THE INVENTION [0010]In accordance with an embodiment of the present invention, a method of sealing a glass envelope is disclosed comprising a first glass substrate having first and second alignment marks. A second glass substrate having third and fourth alignment marks, and comprising at least one frit wall disposed thereon, is aligned to the first substrate by translating the first substrate relative to the second substrate, and aligning the second and fourth alignment marks by rotating the first substrate relative to the second substrate. The translating is accomplished along one or both of orthogonal axes in the plane of the first substrate. The resulting stack is then sealed by heating and melting the at least one frit wall with a laser. [0011]In another embodiment, a method of sealing a glass envelope is provided comprising positioning a first substrate comprising first and second alignment marks on an alignment table having an axis of rotation such that the axis of rotation passes through the first alignment mark, positioning a second substrate comprising third and fourth alignment marks over the first substrate, the second substrate including a frit deposited thereon, aligning the first alignment mark with the third alignment mark, rotating the first substrate about the axis of rotation to align the second alignment mark with the fourth alignment mark, and heating the frit with a laser beam to melt the frit and form a hermetic seal between the first and second substrates [0012]In still another embodiment, an apparatus for assembling and sealing a glass envelope is disclosed comprising a rotatably mounted alignment table for receiving a substrate, the alignment table being movable along x and y directions in a plane, the x and y directions being mutually orthogonal, a substrate transporter for transporting the first substrate to the alignment table and a laser sealing system for sealing a second substrate having a frit deposited thereon to the first substrate. [0013]Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. [0014]It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate an exemplary embodiment of the invention, and together with the description serve to explain the principles and operations of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0015]FIG. 1 is a perspective view of an apparatus for assembling and sealing glass substrates to form a glass envelope according to an embodiment of the present invention; [0016]FIG. 2 is an top-down illustration of the movement (translation and rotation) of a first substrate relative to a second substrate using alignment marks to align the first and second substrates. [0017]FIG. 3 is a top view of first and second substrates, showing exemplary positioning of OLED devices and frit walls, and exemplary positioning of alignment marks. [0018]FIG. 4 is a cross sectional view of a first substrate having OLED devices disposed thereon, and it's positioning relative to a second substrate having frit walls disposed thereon, prior to final assembly and sealing. [0019]FIG. 5 is a perspective view of an apparatus for assembly and sealing of glass substrates to form a glass envelope [0020]FIG. 6 is a partial perspective view of the apparatus of FIG. 5 showing the rail and sealing systems. Continue reading... Full patent description for Method of sealing a glass envelope Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method of sealing a glass envelope patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Method of sealing a glass envelope or other areas of interest. ### Previous Patent Application: Device for ellipsometric two-dimensional display of a sample, display method and ellipsometric measurement method with spatial resolution Next Patent Application: Leveling algorithm for semiconductor manufacturing equipment and related apparatus Industry Class: Optics: measuring and testing ### FreshPatents.com Support Thank you for viewing the Method of sealing a glass envelope patent info. IP-related news and info Results in 0.95631 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error |
||
